Seed germination and conservation of endangered species from the Italian Alps: Physoplexis comosa and Primula glaucescens.

Physoplexis comosa and Primula glaucescens, endemic to calcareous grasslands of the Lombardy Prealps, northern Italy, are protected under Annex IV of European Community Directive 92/43/EEC. Seed germination dynamics of these species were studied with the aim of producing appropriate germination protocols for use in ex situ conservation. Seeds were collected from Monte Barro (922 m a.s.l.) and for Primula glaucescens from three additional sites in a more central part of its range (1217–2521 m a.s.l.). Physoplexis comosa germinated only in sterile in vitro conditions, in which germination percentages were extremely low without a supply of gibberellic acid (GA3; 1.7%); the optimum GA3 concentration was 100 mg l1 (> 90% germination), with lower germination at higher doses of 250–500 mg l1. Primula glaucescens germinated in both sterile and non-sterile conditions and, although total germination was not affected by GA3 concentration, doses of 10–500 mg l1 acted equally to prompt earlier and more rapid germination. Primula glaucescens from Monte Barro was characterised by slower and poorer germination than from central sites.